Tempelman / Shercliff / Eyben Manufacturing and Design

Understanding the Principles of How Things Are Made
1. Auflage 2014
ISBN: 978-0-08-099926-5
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 310 Seiten

Manufacturing and Design presents a fresh view on the world of industrial production: thinking in terms of both abstraction levels and trade-offs. The book invites its readers to distinguish between what is possible in principle for a certain process (as determined by physical law); what is possible in practice (the production method as determined by industrial state-of-the-art); and what is possible for a certain supplier (as determined by its production equipment). Specific processes considered here include metal forging, extrusion, and casting; plastic injection molding and thermoforming; additive manufacturing; joining; recycling; and more. By tackling the field of manufacturing processes from this new angle, this book makes the most out of a reader's limited time. It gives the knowledge needed to not only create well-producible designs, but also to understand supplier needs in order to find the optimal compromise. Apart from improving design for production, this publication raises the standards of thinking about producibility. - Emphasizes the strong link between product design and choice of manufacturing process - Introduces the concept of a 'production triangle' to highlight tradeoffs between function, cost, and quality for different manufacturing methods - Balanced sets of questions are included to stimulate the reader's thoughts - Each chapter ends with information on the production methods commonly associated with the principle discussed, as well as pointers for further reading - Hints to chapter exercises and an appendix on long exercises with worked solutions available on the book's companion site: http://booksite.elsevier.com/9780080999227/

Erik Tempelman is an Associate Professor of Industrial Design Engineering at Delft University of Technology. A respected teacher, Erik has won several prizes for his style and enthusiasm in education, including the 'Best Teacher of the Year Award' in 2009. He has published on a range of subjects, from automotive materials selection to engineering education.

Autoren/Hrsg.

Tempelman, MSc

Shercliff, Hugh

Eyben, Bruno Ninaber van

Leseproben

Chapter 2

Product Disassembly Studies

Chapter Outline

2.1 Introduction

2.2 Outdoor Design: Bus Shelters

2.3 Indoor Design: Domestic Extraction Hood

2.4 Product Disassembly Studies

2.5 Further Reading

2.1 Introduction

This book aims to familiarize you with the main manufacturing processes, as well as their possible applications in all sorts of products. This require a hands-on approach, whereby you actively study the products you encounter in everyday life and ask yourself how they are made. Indeed, most chapters begin with an exercise designed to stimulate you to do precisely this: for instance, Chapter 3 on casting of metals asks you to identify several cast parts and products right from the start. It might be tempting to limit yourself to an image search on the Internet, or even to skip those exercises altogether, but that would be a mistake. It is important to have such products at hand, so you can not only see them from a distance and at just one angle, but look at them closely, from all angles, and literally get a feel for the component. This way, many of the theoretical and practical concepts covered in this book will come much more alive.

This chapter is intended to help you make these instructive explorations. Section 2.4 introduces you to product disassembly studies, which basically involve taking products apart, considering how their various components are made, and finding out how they have been assembled together. If you are technically inclined (which every student of design and engineering must be to some extent: otherwise, why choose such studies?), you have probably already taken apart quite a few products during your lifetime, and you can now learn how to take this hobby to the next level. One quick warning: always consider safety, and never put yourself, or others, at risk.

Before setting you off on disassembly of products, we show a few exemplars of everyday products and discuss how they were made. As you will see, nearly all of the manufacturing processes covered in Chapters 3 to 12 are encountered in these sample products. Of course, many more could have been included, but because this book aims to be selective, we limit ourselves to just two products: one outdoor application and one typical indoor product, both examples of industrial design.

Exercise 2.1

Find a product that is ready for recycling or disposal—for example, an old vacuum cleaner, coffee machine, or computer, or perhaps something bigger such as a lawnmower (preferably products that contain mainly metals and/or plastics). Save it for Section 2.4!

2.2 Outdoor Design: Bus Shelters

Bus shelters come in all sorts and sizes. Over the past decades, their design and manufacture has developed to a degree of sophistication that may be surprising at first, but that becomes readily apparent to anyone who gives these objects a closer look—and considering that if you use them you inevitably spend some time in them, we suggest you do so. Here, we present a bus shelter known as “De Gouwe,” designed for various municipalities and provinces in the Benelux region. It is currently manufactured by the company Epsilon Signs in Bree, Belgium, with placement and maintenance done by the company OFN in Buren, The Netherlands. Fabrique Public Design in Delft, The Netherlands, was responsible for its design. All information and illustrations in this section are courtesy of this design bureau, which has been active in bus shelter design since 1993.

Figure 2.1 shows an exploded view of one version of De Gouwe with its main components and how it looks in the street. Since its introduction into the market in 2009, more than 4,000 of these shelters have been installed in the Benelux countries, in various versions and color schemes. Manufacturing this shelter involves a variety of processes: aluminum extrusion (support poles, roof frame, various smaller parts), metal casting (various parts of the bench and garbage bin), concrete casting (base plate, with inserts for easy assembly of the other components), and sheet metal forming (roof plates, various parts of bench and bin). It also involves a fair number of standard components that are bought in, such as glass panels and lighting elements. Assembly relies on screws, bolts, and other mechanical fasteners; welding (for the roof frame profiles); and clamping. Finishing involves powder coating (for sheet metal parts, certain extrusions) and anodizing (all other extrusions). In total, the De Gouwe shelter contains 729 parts, 168 of which are uniquely designed and manufactured for this shelter—that is, product-specific parts (of which 12 are custom-made fasteners). In total, it contains 575 fasteners. Some noteworthy details are as follows:

Figure 2.1 Exploded view of the “De Gouwe” bus shelter. (Inset: the “De Gouwe” in real life.) (Images courtesy of Fabrique Public Design, Delft, NL)

• All metal castings are made from aluminum using the sand casting method. This requires a modest investment for the casting molds. The method offers a large form freedom and is well suited for the relatively modest production volumes involved (Chapter 3). The castings are cleaned after manufacture and receive a double layer of powder coating (Chapter 13).

• Like the castings, all extrusions are also made specifically for this shelter. This requires some investment for the extrusion dies, but the benefit is that extrusion allows integration of all kinds of assembly functions into the extruded profile (Chapter 5); Figure 2.2 provides an example. The extrusions are either anodized or powder coated to get the right “look and feel” as well as corrosion resistance (Chapter 13).

Figure 2.2 Cross section of extruded rear-right side profile, with integrated glass panes and fasteners. (Image courtesy of Fabrique Public Design, Delft, NL)

• The sheet metal roof panels are made from galvanized low carbon steel. They are made by first cutting, or “blanking,” the input sheet material into the right cutout shape, then bending its four edges, and finally powder coating. All of this can be done using universal equipment, so no investments are needed for these parts (Chapter 4).

The shelter involves three major sub-assemblies: the advertising box, the bench, and the garbage bin; the latter is shown in Figure 2.3. Note how it combines castings, extrusions, and sheet metal parts. The side panels are decorative only and, like the shelter’s roof frame, can be powder coated in any color as desired. Such combinations of processes are in fact common, with complex parts being cast in metal or molded in plastic, less complex profiles being extruded or roll formed, and simpler parts being made by sheet metal forming or plastic thermoforming.

Figure 2.3 Exploded view of garbage bin, with cast concrete foot. (Image courtesy of Fabrique Public Design, Delft, NL)

As a bus shelter, the De Gouwe is very successful, thanks to a number of key design decisions. First, it has a modular design, which allows a range of shapes, sizes, and color schemes with the same set of basic components. This modularity also allows fast assembly indoors, with a total assembly time of under four hours per shelter by a crew of one. Once assembled, the shelter is ready for placement in the street. Connecting it to the power network can be time consuming, but with an optional PV module and battery to provide electricity for lighting, the shelter becomes fully self-sufficient and can be placed in under 10 minutes. Furthermore, its minimalist design is not only aesthetically pleasing but minimizes the accumulation of street dirt and facilitates maintenance, which in turn keeps operating costs low. Of course, it is not vandal-proof, but cracked windows and other damage can be quickly and efficiently repaired. In fact, with the revenue from the advertisements in its poster frame, the shelter can actually bring in money. Durability helps, too: the design life span is 20 years, thanks to corrosion- and wear-resistant materials. Finally, costs have been reduced not only by the modular design but also by careful optimization of all parts, pushing the manufacturing technology to the limits without impairing quality. For instance, the wall thickness of all extrusions has been minimized, saving weight and, hence, costs.

Of course, despite its success, De Gouwe represents only one approach out of many possibilities, and several contemporary alternatives can be found, such as using steel for the main structure instead of extruded aluminum, or using a wooden bench instead of a metal one. The perfect bus shelter simply does not exist. But De Gouwe illustrates very well how various manufacturing processes can be successfully combined. Take a good look at a bus shelter, next time you find yourself in one, and try to see how it was made and which materials and processes were used!

2.3 Indoor Design: Domestic Extraction Hood

In most domestic kitchens, you will find an extraction...